Bike sharing programmes have grown from just 24 cities worldwide a decade ago to more than 800 cities today, but how has a 200-year-old device suddenly become the next big thing in urban transport? The key is digital information, the real-time GPS technology that allows the bikes to be tracked and secured, and lets cities monitor how and where they are being used.

Some cities have also begun posting this GPS data online, allowing the public to come up with their own innovative uses. One fascinating example comes by way of two visual design researchers in Potsdam, Germany: Till Nagel and Christopher Pietsch have used bike sharing GPS data from three global cities to create living, breathing portraits of the cities themselves.

The cf. city flows interactive installation is hosted by Potsdam’s Urban Complexity Lab. Three high-resolution screens let visitors compare flows of urban mobility in London, New York City and Berlin, as seen through the journeys of shared bikes.

As soon as you compare these cities’ patterns of movement, several distinguishing features become apparent. As noted on the project’s website, some visitors pointed out the barrier between Middle Manhattan and Central Park, as well as the inner-city area in Berlin. Others noted the contrast between New York’s neatly ordered street grid and the idiosyncratic, organically-grown layouts of Berlin and London.